10.2 Acids and Bases

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Acids and Bases

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​Class Announcements:

​School Announcements:
No School 26th

• ​Naming

• Properties of Acids and Bases

• pH

• Strength of acids and bases

Properties of Acids

• Produces H⁺ ions in water

• pH lower than 7 (We will learn the pH scale)

• Taste sour

• Electrolytes
  

​DO NOT TASTE ACIDS IN THE LABORATORY!!
* Strong acids can dissolve through metals, teeth, and bone.

Multiple Choice

increases the concentration of H⁺ ions in solution

• acids

• bases

• both

Multiple Choice

tastes sour

• acid

• base

• both an acid and a base

Multiple Choice

Has a pH less than 7

• acid

• base

• both an acid and a base

Acid Reactions

• Acids react with metals forming salt and Hydrogen gas

  • Acidic Corrosion (damage metals)

  • metal + acid ---> salt + Hydrogen

Multiple Choice

Magnesium + sulphuric acid --> ?

• magnesium sulfate + water
• magnesium sulfate + hydrogen
• magnesium chloride + hydrogen

Properties of Bases

• Produces OH^- ions in water

• pH higher than 7

• Taste bitter

• Electrolytes

• Feel slippery or soapy
  

​DO NOT TASTE ACIDS IN THE LABORATORY!!
* Strong bases are just as dangerous as strong acids.

Multiple Choice

Tastes bitter

• acid

• base

• both an acid and a base

Multiple Choice

Bases have a pH value of...

• 7
• more than 7
• less than 7

Lab Testing for Acids and Bases

• Litmus paper (pH)

  • Blue Acids turn red

  • Red Bases turn blue

• Chemical Indicators

  • Change color

• pH meter

  • Concentration of H⁺

Multiple Choice

Which of the following statements is correct?

• Blue litmus paper turns red when placed in a base.
• Red litmus paper turns blue when placed in a base.

Multiple Choice

Which of the following statements is correct?

• Blue litmus paper turns red when placed in an acid.

• Red litmus paper turns blue when placed in a base.

Arrhenius Classification of Acids and Bases

• Acids: create H⁺ ions in a solution

  • Solutions with more H⁺ ions

• Bases: create OH^- ions in solution

Multiple Choice

NaOH is:

• an Arrhenius base

• an Arrhenius acid

• neither an acid nor a base

Bronsted-Lowry Model

• Acids are proton donors (H⁺)

• Bases are proton acceptors

Acids and Bases can form conjugate (linked) pairs
*The acid donates the proton (becoming negative)
*The base gains a proton (becoming positive)

Acid-Base Reactions with Water

acid + H₂O = base + H₃O

H₂O + base = OH^- + acid

​Water can act as both an acid and a base, a process called autoionization

Multiple Choice

According to Bronsted-Lowry, which of the following will "donate" an H⁺ ion?

• Acid

• Base

• Water

Conjugate Pairs

Labelling

Label the acid, base, conjugate acid and conjugate base.

Drag labels to their correct position on the image

conjugate base

acid

base

conjugate acid

Neutralizing Reactions

• Strong acids and strong bases react to form a salt and water with a pH of 7.

  • a salt is an ionic compound that has a cation other than H+ and an anion other than OH-.

• This kind of reaction always produces water and is known as a neutralization reaction

Multiple Choice

A neutralization reaction will (almost) always produce...

• water & salt
• water
• salt
• water & carbon

Multiple Choice

Identify the salt in the following equation:
Zn(OH)₂ + HNO₃   ---> H₂O  + Zn(NO₃)₂

• Zn(OH)₂
• HNO₃
• H₂O
• Zn(NO₃)₂